Heterogeomys dariensis Goldman 1912

30.

Darien Pocket Gopher

Heterogeomys dariensis

French: Gaufre du Darien / German: Darien-Taschenratte / Spanish: Tuza de Darién

Taxonomy. Macrogeomys dariensis Goldman, 1912,

“Cana (altitude 2,000 feet), in the mountains of Eastern Panama [= Darien Province].”

Placed into subgenus Macrogeomys. Heterogeomys considered a subgenus of Orthogeomys by J. L. Patton in 2005 but was resurrected to genusstatus by T. A. Spradling and colleagues in 2016. Molecular studies suggest that FH. dariensis is sister to H. cavator. Orthogeomys thaeleri was formerly recognized as a separate species but was synonymized under H. dariensis by Spradling and colleagues in 2016. Two subspecies recognized.

Subspecies and Distribution.

H.d.dariensisGoldman,1912—EPanama(Darién)intoNWColombia(Choco).

H. d. thaeler: Alberico, 1990 — coastal regions of NW Colombia (Choco).

Descriptive notes. Head-body 210-278 mm,tail 120-140 mm; weight 450-850 g. Dorsal pelage of the Darien Pocket Gopher is reddish brown to dull chocolate brown or nearly black in some individuals. Ventral pelage is sparse and grayish to light brown. Upper surfaces of feet and tail are either brownish, dark pinkish, or nearly white. The Darien Pocket Gopher has a fusiform body shape typical of all pocket gophers and possesses fur-lined cheek pouches that open external to the mouth. Anterior surface of each upper incisor has a single medial groove. Chromosomal complement has 2n = 44 and FN = 78.

Habitat. Well-drained soils in forests, forest clearings, and cultivated regions in eastern Panama and lowland habitats along the Pacific Coast of north-western Colombia. Elevational range is from near sea level to ¢.1200 m.

Food and Feeding. There is no specific information available for this species, but the Darien Pocket Gopher probably feeds on roots, tubers, stems, and leaves of most plants available within the vicinity ofits burrow system. It readily invades cultivated fields and is considered an agricultural pest whereverit occurs in contact with humans. As in all other pocket gophers, the burrow system is a series of shallow feeding tunnels radiating spokelike from a deeper, central network that contains one or more nest chambers and several smaller chambers for storage of food or fecal pellets. In clayey lateritic soils of northwestern Colombia, tunnels of the Darien Pocket Gopher are much shallower (only a few cm below the surface) than tunnels typically produced by large pocket gophers.

Breeding. Pregnant Darien Pocket Gophers have been captured in November-February, and litters have 2-3 young.

Activity patterns. There is no specific information available for this species, but the Darien Pocket Gopher is probably active at any hour of the day, with periods of peak activity around dawn and dusk. It does not hibernate and is active year-round.

Movements, Home range and Social organization. There is no specific information available for this species, but the Darien Pocket Gopheris likely solitary and aggressively territorial. Individuals probably leave their burrow systems only rarely, meaning that their home range is defined by size and extent of their burrow system.

Status and Conservation. Classified as Least Concern on The IUCN Red List (as Orthogeomys dariensis).

Bibliography. Hafner (2015), Hafner & Hafner (1987), Patton (2005b), Reid (1997), Samudio & Pino (2008c), Spradling et al. (2016), Sudman & Hafner (1992).